1. Technical Field
The disclosure is related generally to steam turbine systems. More particularly, the disclosure is related to a cooling fluid flow control system for a high pressure turbine section of a steam turbine system and a related program product.
2. Related Art
Conventional steam turbine systems are frequently utilized to generate power for, e.g., electric generators. More specifically, a working fluid, such as steam, is conventionally forced across sets of steam turbine blades, which are coupled to the rotor of the steam turbine system. The force of the working fluid on the blades causes those blades (and the coupled body of the rotor) to rotate. In many cases, the rotor body is coupled to the drive shaft of a dynamoelectric machine such as an electric generator. In this sense, initiating rotation of the steam turbine system rotor can initiate rotation of the drive shaft in the electric generator, and cause that generator to generate an electrical current (associated with power output).
The amount of power generated by the steam turbine during operation may be dependent upon, at least in part, the temperature of the working fluid (e.g., steam) flowing through the system. That is, the higher the temperature of the working fluid flowing through the steam turbine system, the greater the amount of power generated by the steam turbine system. However, as the temperature of the working fluid increases and the internal temperature of the steam turbine system increases, the risk of undesirable effects within the steam turbine system also increases. More specifically, when the temperature of the working fluid surpasses a predetermined desirable temperature, the risk of undesirable defects, such as deformation or “creep” of the internal components, within the steam turbine system significantly increases.
In order to provide steam turbine systems that operate at elevated pressure and temperature states (e.g., at supercritical or even ultra-supercritical conditions) and prevent the above-described negative impacts, new systems are now being provided with a cooling system to provide a cooling fluid to the wheel space of the high pressure turbine section of the steam turbine system during operation. More specifically, the cooling system may provide cooling fluid to, for example, the wheel space of a high pressure (HP) turbine section and the region of the HP turbine section surrounding the rotor during operation. The cooling fluid of the cooling system may substantially regulate the internal temperature of the wheel space of the steam turbine system from reaching an undesirable temperature. This regulation of the internal temperature may ultimately prevent the steam turbine system and/or the internal components of the steam turbine system from being negatively impacted by high temperature steam.
Cooling systems have been developed to regulate the internal temperatures of cooling fluid. However, the HP turbine section temperature can also be controlled by the flow rate of the cooling fluid provided to the HP turbine section based on the operational characteristics of the system. However, because the operational characteristics vary over time (e.g., internal temperature fluctuation, clearance changes due to wear, varying loads, etc.), the new cooling systems may provide cooling fluid which may over-cool or under-cool the steam turbine system due to an undesirable high flow rate of the cooling fluid. In this instance, the new cooling systems may also temporarily cause a decrease in efficiency of the steam turbine system and ultimately the amount of power generated by the system.